ASTM D3596-92(2001)
(Practice)Standard Practice for Determination of Gels (Fisheyes) In General-Purpose Poly(Vinyl Chloride) (PVC) Resins
Standard Practice for Determination of Gels (Fisheyes) In General-Purpose Poly(Vinyl Chloride) (PVC) Resins
SCOPE
1.1 This practice provides a quantitative measure of the gels remaining in a flexible vinyl compound processed from general-purpose poly(vinyl chloride) (PVC) resins under a prescribed set of working conditions.
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Note 1—There are no ISO standards covering the primary subject of this practice.
General Information
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Standards Content (Sample)
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Designation:D3596–92 (Reapproved 2001)
Standard Practice for
Determination of Gels (Fisheyes) In General-Purpose
Poly(Vinyl Chloride) (PVC) Resins
This standard is issued under the fixed designation D 3596; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 5. Significance and Use
5.1 The gel (fisheye) in PVC resins is generally recognized
1.1 This practice provides a quantitative measure of the gels
remaining in a flexible vinyl compound processed from as a hard particle of resin which will not fuse when the plastic
general-purpose poly(vinyl chloride) (PVC) resins under a mass is subjected to set conditions of hot processing. The
prescribed set of working conditions. number of unfused particles present is related to the conditions
1.2 The values stated in SI units are to be regarded as the used.The presence of an excess of such particles is detrimental
standard. The values in parentheses are for information only. to many applications.
1.3 This standard does not purport to address all of the
6. Apparatus
safety problems, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 6.1 Laboratory Mixer, with stainless steel mixing bowl.
6.2 Two-Roll Mill, 152.4 by 304.8 mm (6 by 12 in.), 263.55
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. mm (10.5 in.) between guides, differential speed ratio 1.40 6
0.04, fast roll speed 34 6 2 rpm, suitably heated to maintain
NOTE 1—There are no ISO standards covering the primary subject of
roll temperature of 154 6 3°C (310 6 5°F).
this practice.
NOTE 2—If the mill available does not meet these criteria, the specifi-
2. Referenced Documents
cations of the mill used should be included in the report.
2.1 ASTM Standards:
6.3 Surface Pyrometer calibrated in the range of 154°C
D 883 Terminology Relating to Plastics
(310°F) and a leaf pyrometer calibrated in the range of 163°C
D 1249 Specification for Octyl Ortho-Phthalate Ester Plas-
(325°F).
ticizers
6.4 Balance, 0.1-g sensitivity.
D 1600 Terminology for Abbreviated Terms Relating to
6.5 Hydraulic Press having platens at least 203 by 203 mm
Plastics
(8 by 8 in.), rated at a minimum of 140 MPa (20 000 psi) ram
pressure on a 100-mm (4-in.) ram, which may be heated to 163
3. Terminology
6 3°C (325 6 5°F) on the pressing surfaces and equipped with
3.1 General—Definitions are in accordance with Terminol-
cooling water.
ogy D 883 and abbreviations with Terminology D 1600, unless
6.6 Timer, capable of being read in seconds.
otherwise indicated.
6.7 Cotton Gloves.
6.8 Mill Knife.
4. Summary of Practice
6.9 Plates or Mold, two 203 by 203-mm (8 by 8-in.)
4.1 A sample of PVC resin is mixed with calcium stearate
chrome-platedferroplates,orachrome-platedmoldwitha152
and di-2-ethylhexyl phthalate plasticizer (DOP) in a laboratory
by 152 by 6.4-mm (6 by 6 by 0.25-in.) cavity.
mixer. After mixing, the dry blend is milled on a two-roll
6.10 Backing Plates, two 203 by 203 by 6.4 mm (8 by 8 by
laboratory mill; carbon black dispersion is added during the
0.250 in.).
milling.
6.11 BrassShims, four, 0.51 by 13 by 203 mm (0.020 by 0.5
4.2 The milled sheet is press-polished and the gels counted
by 8.0 in.).
using a bottom-lighted viewing box and a magnifying com-
6.12 Magnifying Comparator, equipped with a transparent
parator.
reticule (scale) showing circles from 0.03 to 1.27 mm (0.001 to
0.050 in.) in diameter.
This practice is under the jurisdiction ofASTM Committee D20 on Plastics and
is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials.
Current edition approved October 15, 1992. Published December 1992. Origi- The Hobart Model N-50 is satisfactory.
nally published as D 3596 – 77. Last previous edition D 3596 – 88. AComparator supplied by Finescale Co. of LosAngeles, CA, equipped with a
Annual Book of ASTM Standards, Vol 08.01. No. 128 reticle has been found suitable for this application.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3596
6.13 Bottom-Lighted Viewing Box. 8.3 Cut a 152 by 152-mm (6 by 6-in.) section from the
milled stock.
7. Materials
8.3.1 Placethesectioncutfromthemilledsheetbetweenthe
two chrome-plated ferro plates, chrome side to the specimen,
7.1 PVC Resin.
then put the chrome ferro plates and the specimen between the
7.2 DOP, Specification D 1249, Type 1.
backing plates and insert in a press at 163 6 3°C (325 6 5°F).
7.3 Calcium Stearate.
Preheat for 0.5 min with the press closed at zero pressure. A
7.4 Carbon Black Dispersion.
chrome-plated mold can be used instead of the plates.
8. Procedure
8.3.2 After preheating, apply ram pressure for 2 min. Use
enoughpressuretoproduceasheetthicknessof0.5 60.03mm
8.1 Weigh300gofthesampleresin,9gofc
...
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